Compasses with improved adjustment means



Oct. 25, 1966 H. HEIMBERGER 3,

COMPASSES WITH IMPROVED ADJUSTMENT MEANS Filed July 27, 1964 2Sheets-Sheet l INVENTOR H. Heimberger Oct. 25, 1966 H. HEIMBERGER3,280,466

COMPASSES WITH IMPROVED ADJUSTMENT MEANS Filed July 27, 1964 2Sheets-Sheet 2 INVENTOR H. Heimberger United States Patent 3,280,466COMPASSES WITH IMPROVED ADJUSTMENT MEANS Helmut Heimberger, Essen(Ruhr), Germany, assignor to Clemens Riefler Fabrik MathematischerInstrumeute, Postfach, Germany Filed July 27, 1964, Ser. No. 385,122Claims. (Cl. 33-154) This invention relates to improved draftinginstruments and, more particularly, to compasses of the type having aspindle and associated screw member arranged to adjust-ably connect thearms of the compass to one another; the improved arrangement being suchthat a rapid major adjustment of the arms can be made without turningthe adjustment screw, said adjustment screw serving primarily to makefine adjustments.

Various forms of compass and drafting instrument adjusting mechanismshave been suggested heretofore. As a general matter, when the adjustingmechanism has included a spindle and associated screw member, everyadjustment (whet-her large or small) has required turning of said screwmember until the new desired radius, or relative arm positions, havebeen achieved. As a result, prior compasses of this general design havepermitted fine adjustments only by means of the spindle, without anypossibility of the compass arms being moved in a rapid major adjustment;and the operation of such known com-passes has, therefore, beendifficult and timeconsuming. The primary object of the presentinvention, recognizing this situation, resides in the provision ofimproved form of adjusting mechanism, for use on compasses or otherinstruments of the general type described; so arranged that, in additionto fine adjustments, a rapid major adjustment becomes possible.

The invention effects this improved operation by providing an adjustingmechanism which includes at least one nut, constructed and arranged tobe resilient in its radial directions within the range of its thread, inassociation with a spindle having a thread adapted to effect a radialdistortion, or resilient pushing-away, of the nutthread when the compassarms are manually expanded and compressed relative to one, another. Theimproved structure of the present invention thus makes it feasible toeffect a rapid major adjustment, of the arms of the compass, prior to afine adjustment there-of, simply by expanding or compressing the compassarms. By such manipulation of the compass arms (or of similar adjustablyinterconnected parts of other instruments), the thread of the nut (or ofboth nuts if such nuts are arranged within both arms of the compass)will be resiliently distor-ted, thereby to permit a rapid majoradjustment of said arms or interconnected parts; and fine adjustmentscan thereafter by made by turning the spindle. Thus, the instrumentscontemplated by the present invention can be precisely adjusted in amuch shorter period of time than has been possible heretofore.

In order to facilitate movement of the spindle within the aforementionedresilient nut, or nuts, respectively, the spindle can be provided with aknuckle or a buttress thread. The nut, 01' nuts, can be made from anyapppropriate resilient material, either natural or synthetic; butpreferably comprise a resilient homogeneous substance fabricated on thebasis of the polyester-isocyanate additive reaction. As will alsoappear, the nuts can be provided with a preformed thread adapted to beengaged by complementary threads on the spindle, substantially free fromplay; or, in the alternative, the resilient nuts can also be made withan unthreaded bore, which bore has a diameter smaller than the outerdiameter of the spindle, so that as the spindle is screwed into the saidbore, it forms a counter-thread in the nut, or nuts, with which saidspindle is associated.

The term resilient materia is used herein, and in the appended claims,in its normally accepted sense, i.e. it refers to the capability of amaterial to elastically deform temporarily upon the application offorces thereto, and, upon removal of said forces, to return to itsoriginal position, shape and size.

The foregoing objects, advantages, construction and operation of thepresent invention will become more readily apparent from the followingdescription and ac companying drawings, in which:

FIGURE 1 shows one form of compass constructed in accordance with theinvention;

FIGURE 2 shows another form of compass constructed in accordance withthe invention;

FIGURE 3 is a cross-sectional view of a portion of the right-hand arm ofthe compasses illustrated in both of FIGURES 1 and 2;

FIGURE 4 is an end view of the structure illustrated in FIGURE 3;

FIGURE 5 is a cross-sectional view illustrating a portion of a compassor instrument arm constructed in accordance with a further species ofthe present invention;

FIGURE 6 is an end view of the structure shown in FIGURE 5;

FIGURE 7 is a detail view of a portion of a spindle adapted for use inthe present invention and having a buttress thread;

FIGURE 8 is a detail view of a portion of an alternative spindle adaptedfor use in the present invention and having a knuckle thread;

FIGURE 9 is a cross-sectional view illustrating a portion of a compassor instrument arm constructed in accordance with still another speciesof the present invention;

FIGURE 10 is an end view of the structure shown in FIGURE 9;

FIGURE 11 is a cross-sectional view illustrating a portion of a compassor instrument arm constructed in accordance with a still further speciesof the inveniton;

FIGURE 12 is a cross-sectional view illustrating a portion of .a compassor instrument arm constructed in accordance with still another speciesof the present invention;

FIGURE 13 is an end view of the structure shown in FIGURE 12;

FIGURE 14 is a cross-sectional view illustrating a still further speciesof the present invention;

FIGURE 15 is a cross-sectional view of a portion of an arm correspondingto still another species of the present invention; I

FIGURE 16 is an end view of the structure shown in FIGURE 15;

FIGURE 17 illustrates still another species of the present invention;

FIGURE 18 is an end view of the structure shown in FIGURE 17;

FIGURE 19 illustrates a still further .species of the invention;

FIGURE 20 is an end view of the structure shown in FIGURE 19; and

FIGURE 21 is a top cross-sectional view of the structure shown in FIGURE19.

The compass illustrated in FIGURE 1 has a head structure 2 provided witha handle 1, and having a pair of arms 3- and 4 swivel-mounted withinsaid head structure 2. The compasses can be provided with any desiredtype of guide structure for causing the handle 1 to be located at alltimes along a line bisecting the angle formed by the two arms 3 and 4.Arm 4 is provided with a recess 5, as shown in FIGURES 3 and 4, intowhich is inserted a nut 6. The contact areas 7 and 8 of the recess 5, aswell as the corresponding areas of nut 6, are circular segments so thatthe nut 6 is adapted to pivot within the recess of said arm 4. A spindle9 passes through nut 6, spindle 9 being provided with either a buttressthread, of the type shown in FIGURE '7, or with a knuckle thread of thetype shown in FIGURE 8. Nut 6 has two generally parallel surfaces 10,spaced from one another by a distance less than the distance between theedges 11 of the recess 5. The said nut 6 may be mounted in recess 5 ofarm 4 by initially inserting the nutinto recess 5 in such manner thatthe said parallel surfaces extend generaliy in the direction ofextension of arm 4, whereafter the nut 6 is turned until it reaches theposition shown in FIGURE 3. Nut 6 can consist of a resilient material,for example, a resilient synthetic material, preferably a resilienthomogeneous substance fabricated on the basis of thepolyester-isocyanate additive reaction. Said resilient nut 6 can also beprovided with an internal thread of one of the types shown in FIGURES 7and 8, so that the thread of said out may be engaged, free of play, by acor-responding thread on the spindle 9.

The other arm 3, in the species of compass depicted in FIGURE 1, is alsoprovided with a recess similar to recess 5 of arm 4, into which recessis inserted a component 6 designed in the same manner as the nut 6 butprovided, in place of a thread, with a through-bore in which the spindle9 is rotatably but not axially movable. Moreover, in the species ofFIGURE 1, the left end of the spindle 9 is provided with a knurled knob12 which facilitates the turning of spindle 9.

In operation, when it is desired to make a rapid major adjustment of thecompass shown in FIGURE 1, it is merely necessary to physically move thearms 3 and 4 toward or away from one another. When the arms 3 and 4 areso manipulated, the thread of the nut 6 is pushed away or distortedresiliently in radial directions by the spindle 9, thereby in effectpermitting the nut 6 to slide relative to the spindle 9. After a majoradjustment of this type has been accomplished, the distance between thecompass points can then be precisely set by turning the spindle 9through the agency of knob 12.

Obviously, it is also possible to provide nut 6 with a through-borehaving a diameter smaller than the outer diameter of the spindle 9, sothat the spindle will cut its town thread when screwed into the bore.The operation of the instrument still corresponds to that describedabove.

In order to achieve symmetrical movement and positioning of the twocompass arms with respect to the head of the compass, the compass of thepresent invention is preferably provided with a guide member, e.g., thespindle may be provided, at its center, with a circular knurled diskwhich is guided within a slot defined in the head of the instrument.Thus, in the species of compass illustrated in FIGURE 2, resilient nuts6 are inserted in both arms 3' and 4' Within appropriate recesses 5,these nuts being engaged by a spindle 9, provided with either a buttressor a knuckle thread, as depicted by FIGURES 7 and 8. At the center ofspindle 9' there is fastened a knurled disk 12' which is guided within aslot 13 formed in an extension of head member 2' whereby astraight-guidance is accomplished, and symmetrical movement of arms 3',4' is assured. When the two arms 3', 4 are expanded or compressed, thethread of the two nuts 6 will again be pushed resiliently in radiallyoutward directions by the thread of spindle 9, thereby permitting arapid major adjustment of the two arms 3', 4'.

In order to facilitate placement of the nut within the appropriateinstrument arm, the nut may be inserted into a supporting piece, whichsupporting piece is in turn inserted into a transverse bore of the armand then fastened 4 therein, for example by riveting. Thus, in thespecies illustrated by FIGURES 5 and 6, the resilient nut 6, rather thanbeing inserted directly into the instrument arm, is disposed within aninsert 14 which is in turn placed within and riveted to, a recess 15 ofthe compass arm 16.

It is also possible, in accordance with an additional characteristic ofthe invention, to insert the nut into a recess formed in the compass armand opening into one face of said arm transversely to the spindle, saidrecess being covered by means of a disk imbedded in the arm. In thismanner, the manufacture of the nut-receiving recesses within the arms,as well as the mounting of the resilient nuts therein, will be greatlyfacilitated. Thus, in the species of the present invention shown inFIGURES 9 and 10, the instrument arm 17 is provided with a recess 18opening into one face of said arm 17. A resilient nut 19, round in caseof this species, is inserted into said recess 18 and is then secured inposition by a flushrecessed disk 20 appropriately fastened to arm 17. Asin the case of the other species described earlier, nut 19 can again beprovided with either a preformed thread, or with an unthreaded borehaving a diameter smaller than the outer diameter of the spindle 9' sothat the spindle will cut its own thread.

In order to insure permanent resiliency of the nut within the area ofthe spindle thread, the nut is preferably inserted in a metal ringarranged within the arm to avoid any detrimental expansion. Thus, in thespecies of FIG- URE 11, the resilient nut 19 is inserted into a rigidring 21, made for example of metal, fastened within arm 17', in themanner described in reference to FIGURES 9 and 10, and provided withthrough-bores for insertion of spindle 9. The nut 19 again can consistof an appropriate resilient material; and ring 21 tends to assurepermanent resiliency of the nut by preventing any detrimental expansionthereof during coarse or fine adjustments of the instrument.

In accordance with another form of the invention, the nut itself can bemade of an inflexible material and can be provided with an unthreadedbore, the diameter of which bore is equal to, or larger than, the outerdiameter of the spindle; and an insert can then be placed into the nutand pressed against the spindle, which insert consists of a resilientmaterial, preferably a resilient homogeneous substance of the typedescribed previously. When screwed into the insert, the spindle will cutits own counterthreaded so that the nut, and its associated instrumentarm, are retained on the spindle. Again, however, the mechanism isadapted to permit relative sliding motion between the nut and spindleupon compression or expansion of the instrument arms, due to the factthat the aforementioned insert will be resiliently distorted by thespindle in radial directions during such manipulaiton of the instrumentarms. The aforementioned resilient insert can, as will appear, takevarious forms. It may consist, for example, of a wedge placedtransversely into the nut and protruding into the area of the spindle,the spindle cutting the thread into it.

Thus, as shown in FIGURES 12 and 13, the instrument arm 22 maybeprovided with a rigid circular disk 23, made of metal or of syntheticmaterial, positioned for rotation free of play within a recess in arm22, and covered by a plate 24. Rigid circular disk 23 is provided with athrough-bore adapted to receive spindle 9, with the diameter of saidspindle being equal to, or smaller than the diameter of the bore.Inserted into the rigid circular disk 23 is a wedge 25 made of anappropriate resilient material; and, as shown in FIGURES 12 and 13, thewedge insert 25 includes a portion protruding into the thread of spindle9, so that the spindle 9' cuts or resiliently presses a complementarythread into said insert 25 for the purposes already described.

A second wedge can be provided at the other side of the spindle, alsoplaced transversely into the nut and protruding into the area of thespindle. Thus, in the species of FIGURE 14, which is closely related tothat of FIG- URES 12 and 13, the disk 23, which corresponds in functionto the circular disk 23 of FIGURES 12 and 13, has inserted therein apair of identical wedges 25' disposed adjacent opposite sides of thespindle 9'. The second wedge 25', thus added in the species of FIGURE14, likewise protrudes into the area of the thread of spindle 9" in themanner, and for the purposes, already described.

The resilient insert can also consist of a wedge placed into a borevertically to the spindle and pressed against the spindle by means of ascrew. Moreover, the nut can comprise a wedge running transverselythrough the arm, with a screw member applied and fastened thereto insuch manner that it can be serviced from the outside. This arrangementmakes it possible to vary the surface pressure if necessary. Theresilient insert may also take the form of at least one steel ball whichis pressed by spring force into the thread of the spindle which, in thecase of this species, should be hardened. In place of a ball, componentsof any other desired shape can be employed, so long as they aresubjected to a spring force. It is also possible to swivel-mount the nutwithin a recess of the arm by means of a bolt, resulting in greatsimplicity of the recess design and manufacture.

Thus, in the species illustrated in FIGURES 15 and 16, a rigid member29, made of metal or synthetic material, is swivel-mounted for pivotalmovement on a bolt 28 located within a recess 26 of the instrument arm27. Member 29 is provided with a bore 40 for insertion of spindle 9, thediameter of the spindle again being equal to, or smaller than thediameter of the bore 40. The member 29 is provided with another bore 41which extends transverse to the direction of elongation of spindle 9'. AWedge 30 made of resilient material, is inserted into transverse bore41, and is pressed against the spindle 9' by a pressure adjustment screw31.

FIGURES 17 and 18 show a species where a rigid bolt 33, made of metal orsynthetic material, is mounted rotatably free of play within arm 32.Bolt 33 is provided with a bore for insertion of spindle 9', the outerdiameter of said spindle being equal to, or smaller than, the diameterof the bore. The bolt 33 is provided also with another bore whichextends vertically to the spindle 9', and into which is inserted a wedge30, the wedge being pressed against the spindle 9' by a pressureadjustment screw 31' having its head positioned on an outer face of thearm 32 so as to be readily accessible for pressure adjustment purposes.

In another form of the invention, the arm of the compass or otherinstrument can be provided with a throughbore extending transversely ofthe spindle, into which is inserted a pair of wedges extendingrespectively toward both sides of the spindle. The wedges should each bemade of a hard, wear-resistant material; and at least one of thesewedges may be provided with a thread, said wedges being pressed againstthe spindle by means of a resilient bracket which is placed undercompression and which embraces the arm. In order to insure sufiicientsupport, the sides of the bracket may be provided with beveled beadswhich engage corresponding recesses of the two wedges.

Thus, in the species illustrated in FIGURES 19 to 21, the arm 34 isprovided with a through-bore 35 which extends transversely to thespindle 3' and into which are inserted free of play two wedges 36 and37, made of a hard, wear-resistant material such as superpolyamide, saidwedges being pressed against the spindle 9' by a spring bracket 38. Thesides of bracket 38 which embrace arm 34 of the compass are providedwith beveled beads 39 which engage corresponding recesses in the wedges36 and 37, as shown in detail by FIGURE 21. The end, or ends of wedges36 and 37 which extend toward the spindle can be provided with a threadof the type shown by FIGURE 7 or 8.

Having thus described my invention, I claim:

1. A compass comprising a pair of arms movable relative to one another,a threaded rotatable spindle adjustably connecting said arms to oneanother, the threads of said spindle being relatively rigid, a nutmounted within at least one of said arms in engagement with the threadsof said spindle, said nu-t having a thread area adapted to cooperatewith the threads on said spindle for adjusting the positions of saidarms relative to one another upon rotation of said spindle, the threadarea of said nut comprising a homogeneous resilient mate-rial havingportions protruding into the relatively rigid threads of said spindle,said resilient material being constructed to yield temporarily in radialdirections relative to the thread of said spindle in response to theapplication of forces along the axial direction of said spindle and toresiliently resume its original protruding condition relative to therigid threads of said spindle upon removal of said axial forces, wherebysaid spindle and nut may be slidably moved relative to one another bytemporary deformation of said resilient material upon manualmanipulation of said arms toward and away from one another thereby topermit major adjustments in the positions of said arms relativeto oneanother without rotation of said spindle.

2. The compass of claim 1 wherein said nut is inserted into a metal ringdisposed within said arm.

3. The compass of claim 1 wherein said nut comprises a rigid materialprovided with an unthreaded bore, the diameter of said bore being atleast equal to the outer diameter of said spindle, said homogeneousresilient material comprising at least one resilient insert disposedwithin said nut and pressed against said spindle.

4. A compass as claimed in claim 1 wherein said nut comp-rises aresilient synthetic material.

5. The compass of claim 1 wherein said nut is provided with anunthreaded bore comprising said resilient material, the diameter of saidbore, when said resilient material is in an unstressed condition, beingsmaller than the outer diameter of said spindle, whereby the thread areaof said nut is formed automatically by resilient deformation of saidresilient material upon insertion of said spindle into said bore.

6. The compass of claim 5 wherein said nut is disposed within arelatively rigid supporting member, said supporting member beingfastened within said arm.

7. In an instrument having at least first and second members mounted formovement relative to one another, a threaded shaft extending betweensaid members in engagement with portions of both said members wherebythe relative positions of said members may be varied by rotation of saidshaft, at least one of said members including an insert of resilientlyyieldable material engaging said shaft in the thread engagement portionof said one of said members, said insert material temporarily deformingin radial directions automatically in response to the application ofaxial force to said threaded shaft and returning to its original shapeand position relative to said shaft upon removal of said axial forceswhereby the relative positions of said members may be varied withoutrotation of said shaft by slidably moving said member along said shaftto effect a temporary resilient yielding of said insert relative to thethreads of said shaft.

8. An instrument comprising a supporting structure, first and secondelongated arms attached to said supporting structure, at least one ofsaid arms being pivotal-1y attached to said supporting structure wherebysaid elongated arms may assume different angular positions relative toone another, at least said first arm having an elastically yieldablemember attached thereto at a location spaced from said supportingstructure, and a threaded rotatable spindle extending from said secondarm into thread engagement with said elastically yieldable member, thethreaded area of said spindle being relatively rigid to elasticallyreposition said yieldable member automatically in radial directionsrelative to said threaded area of said spindle upon the application ofaxial forces to said threaded area of said spindle, whereby said armsmay be angularly repositioned relative to one another by rotation ofsaid spindle and may also be angularly repositioned relative to oneanother by applying axial forces along said spindle operating toslidably move said first arm relative to said spindle by causing atemporary elastic yielding of said member relative to the threads ofsaid spindle.

9. A compass comprising a pair of arms movable relative to one another,a threaded rotatable spindle adjustably connecting said arms to oneanother, a nut mounted Within at least one of said arms in engagementwith the threads of said spindle, said nut being inserted into a recessin said arm, said recess opening into one face of said arm and beingcovered by means of a disk imbedded into said arm, said nut having athread area adapted to cooperate with the threads on said spindle foradjusting the positions of said arms relative to one another uponrotation of said spindle, the thread area of said nut comprising aresilient material arranged to yield in radial directions relative tothe thread of said spindle, whereby said spindle and nut may be slidablymoved relative to one another upon manual manipulation of said armstoward and away from one another thereby to permit major adjustments inthe positions of said arms relative to one .another Without rotation ofsaid spindle.

10. A compass comprising a pair of arms movable relative to one another,a threaded rotatable spindle adjustably connecting said arms to oneanother, a nut mounted Within at least one of said arms in engagementwith the threads of said spindle, said nut having a thread area adaptedto cooperate with the threads on said spindle for adjusting thepositions of said arms relative to one another upon rotation of saidspindle, the thread area of said nut comprising a resilient materialarranged to yield in radial directions relative to the thread of saidspindle, whereby said spindle and nut may be slidably moved relative toone another upon manual manipulation of said arms toward and away fromone another thereby to permit major adjustments in the positions of saidarms relative to one another without rotation of said spindle, said nutcomprising a rigid material provided with an unthreaded bore, thediameter of said bore being at least equal to the outer diameter of saidspindle, at least one resilient insert disposed within said nut andpressed against said spindle, and an adjustment screw bearing upon saidinsert for adjusting the pressure of said insert against said spindle.

References Cited by the Examiner UNITED STATES PATENTS 334,764 1/1886Fay 33-l54 355,430 1/1887 Wright 33l54 2,392,704 1 /1946 Simmons.2,401,321 6/1946 Schwend 33154 2,552,868 5/1951 Rebitzer 33-1542,588,780 3/1952 Pappelendam 33l54 2,775,916 1/1957 Baxter et al. 85-323,098,304 7/1963 Harris 33-454 FOREIGN PATENTS 722,242 1/ 1955 GreatBritain.

LEONARD FORMAN, Primary Examiner.

ISAAC LISANN, Examiner.

W. D. MARTIN, Assistant Examiner.

1. A COMPASS COMPRISING A PAIR OF ARMS MOVABLE RELATIVE TO ONE ANOTHER,A THREADED ROTATABLE SPINDLE ADJUSTABLY CONNECTING SAID ARMS TO ONEANOTHER, THE THREADES OF SAID SPINDLE BEING RELATIVELY RIGID, A NUTMOUNTED WITHIN AT LEAST ONE OF SAID ARMS IN ENGAGEMENT WITH THE THREADSOF SAID SPINDLE, SAID NUT HAVING A THREAD AREA ADAPTED TO COOPERATE WITHTHE THREADS ON SAID SPINDLE FOR ADJUSTING THE POSITIONS OF SAID ARMSRELATIVE TO ONE ANOTHER UPON ROTATION OF SAID SPINDLE, THE THREAD AREAOF SAID NUT COMPRISING A HOMOGENEOUS RESILIENT MATERIAL HAVING PORTIONSPROTRUDING INTO THE RELATIVELY RIGID THREADS OF SAID SPINDLE, SAIDRESILIENT MATERIAL BEING CONSTRUCTED TO YIELD TEMPORARILY IN RADIALDIRECTIONS RELATIVE TO THE THREAD OF SAID SPINDLE IN RESPONSE TO THEAPPLICATION OF FORCES ALONG THE AXIAL DIRECTION OF SAID SPINDLE AND TORESILIENTLY RESUME ITS ORIGINAL PROTRUDING CONDITION RELATIVE TO THERIGID THREADS OF SAID SPINDLE UPON REMOVAL OF SAID AXIAL FORCES, WHEREBYSAID SPINDLE AND NUT MAY BE SLIDABLY MOVED RELATIVE TO ONE ANOTHER BYTEMPORARY DEFORMATION OF SAID RESILIENT MATERIAL UPON MANUALMANIPULATION OF SAID ARMS TOWARD AND AWAY FROM ONE ANOTHER THEREBY TOPERMIT MAJOR ADJUSTMENTS IN THE POSITIONS OF SAID ARMS RELATIVE TO ONEANOTHER WITHOUT ROTATION OF SAID SPINDLE.